The purpose of this message is to request a new feature be added to
NGINX - “first” load balancing algorithm and MAXCONN setting for
upstream servers.
I am setting up a new site that will require multiple upstream servers
and load balancing. I plan to use ip_hash load balancing on frontend
servers to do simple load balancing to the backend servers. I would
like to protect each backend server from becoming overloaded and
possibly failing because of too many connections sent to it.
I plan on using haproxy to “guard” each backend server by using
haproxy’s “first” load balancing and setting a MAXCONN for the localhost
backend. If the maximum connections for the server is met, haproxy will
send the request to the next server in the list. I also plan on using
Amazon EC2 instances and this set up will not only protect each backend
server from becoming overloaded, it allows me to “spin up” new backend
servers if the last backend server is approaching MAXCONN. Similarly,
if the last two backends in my server farm are not receiving any
requests, I can “spin down” the last server (and save me money!!!).
Now, it seems to me I could remove haproxy from my server software stack
if NGINX added support for “first” load balancing and MAXCONN setting
for each upstream server. I think this should be relatively easy to
support since I see NGINX already supports “least conn” load balancing.
I guess this means that NGINX already knows how many connections it has
open to an upstream server and could easily implement “first” and “max
conn”.
Kevin